1. Field of the Invention
The present invention relates to a scroll compressor, and more particularly, to a discharge valve system of a scroll compressor capable of maximizing a discharge amount of gas compressed in a low pressure ratio operation and capable of minimizing the number of assembly processes by simplifying components.
2. Description of the Conventional Art
Generally, a compressor converts electric energy into kinetic energy, and compresses refrigerant gas by the kinetic energy. The compressor is a core component constituting a refrigerating cycle system, and includes various kinds such as a rotary compressor, a scroll compressor, a reciprocal compressor, etc. according to a compression mechanism for compressing a refrigerant. The compressors are used in a refrigerator, an air conditioner, a showcase, etc. The scroll compressor is divided into a motor part for generating a rotational force; and a compression part for sucking, compressing, and discharging gas by receiving a driving force of the motor part while an orbiting scroll is orbit-motioned with being engaged with a fixed scroll.
FIGS. 1 and 2 are sectional views showing a compression part of a scroll compressor in accordance with the conventional art.
As shown, the compression part of the scroll compressor includes: a fixed scroll 30 mounted in a hermetic container with a certain gap from an upper frame 20 mounted in the hermetic container 10; an orbiting scroll 40 positioned between the upper frame 20 and the fixed scroll 30 to be orbiting-movably engaged with the fixed scroll 30; an oldham ring 50 positioned between the orbiting scroll 40 and the upper frame 20, for preventing a rotation of the orbiting scroll 40; a high/low pressure division plate 11 coupled to the hermetic container 10 with the fixed scroll 30, for dividing inside of the hermetic container 10 into a high pressure region and a low pressure region; and a discharge valve assembly 60 mounted at an upper surface of the fixed scroll 30, for opening and closing a discharge hole 31 formed at the fixed scroll 30.
The orbiting scroll 40 is connected to an eccentric portion 71 of a rotation shaft 70 inserted into the upper frame.
A suction pipe 12 for sucking gas is connected to one side of the hermetic container 10 positioned at the low pressure region, and a discharge pipe 13 for discharging gas is connected to one side of the hermetic container 10 positioned at the high pressure region.
An unexplained reference numeral 32 denotes a wrap of the fixed scroll 30 protruded as an involute curve shape, 41 denotes a wrap of the orbiting scroll 40 protruded as an involute curve shape, and B are bushes.
An operation of the compression part of the scroll compressor will be explained as follows.
First, when the rotation shaft 70 is rotated by receiving a rotational force of the motor part, the orbiting scroll 40 coupled to the eccentric portion 71 of the rotation shaft is orbitingly-moved by having the rotation shaft 70 as a center axis. The orbiting scroll 40 performs an orbiting movement while a rotation thereof is prevented by the oldham ring 50.
As the orbiting scroll 40 performs an orbiting movement, the wrap 41 of the orbiting scroll 40 performs an orbiting movement with being engaged with the wrap 32 of the fixed scroll 30. According to this, a plurality of compression pockets P formed by the wrap 41 of the orbiting scroll 40 and the wrap 32 of the fixed scroll 30 move towards center portions of the fixed scroll 30 and the orbiting scroll 40, and at the same time, volumes of the compression pockets P are varied thereby to suck gas, compress the gas, and discharge the gas through the discharge hole 31 of the fixed scroll 30.
The gas of a high temperature and a high pressure discharged through the discharge hole 31 of the fixed scroll 30 passes through the high pressure region, and is discharged outside the hermetic container 10 through the discharge pipe 13.
The scroll compressor is mainly mounted at an air conditioner with a refrigerating cycle system. At this time, the scroll compressor is operated in a low pressure ratio or a high pressure ratio by considering an efficiency of the scroll compressor according to an installation condition or a driving condition of the air conditioner.
In case that the scroll compressor is operated in a low pressure ratio, gas compressed in the compression pocket P formed by the wrap 32 of the fixed scroll 30 an the wrap 41 of the orbiting scroll 40 is discharged as a middle pressure state through a bypass hole 33 formed at a middle region of the fixed scroll 30. Also, in case that the scroll compressor is operated in a high pressure ratio, gas compressed in the compression pocket P formed by the wrap 32 of the fixed scroll 30 an the wrap 41 of the orbiting scroll 40 is discharged as a high pressure state through the pass hole 31 of the fixed scroll 30.
In case that the scroll compressor is operated in a low pressure ratio or a high pressure ratio, a discharge valve system for discharging gas of a middle pressure state and a high pressure state is provided at the fixed scroll 30.
FIG. 3 is a perspective view showing a discharge valve system of a scroll compressor in accordance with the conventional art, and FIG. 4 is a front sectional view showing a part of the discharge valve system.
As shown, in the discharge valve system, the discharge hole 31 is penetratingly-formed in the middle of the fixed scroll 30. A first double bypass hole 33 having two through holes adjacent to the fixed scroll 30 is formed at one side of the discharge hole 31, and a second double bypass hole 33 having two through holes adjacent to the fixed scroll 30 is formed at another side of the discharge hole 31.
A discharge valve assembly 60 for opening and closing the discharge hole 31 is mounted at an upper surface of the fixed scroll 30. The discharge valve assembly 60 is composed of: a discharge valve 61 formed as a thin plate of a certain shape, for opening and closing the discharge hole 31; a retainer 62 for supporting the discharge valve 61; and a fixing bolt 63 for fixing one side of the discharge valve 61 and the retainer 62.
A first bypass valve assembly 80 for opening and closing the first double bypass hole 33 is mounted at an upper surface of the fixed scroll 30. The first bypass valve assembly 80 is composed of: a bypass valve 81 for opening and closing the first double bypass hole 33; a retainer 82 for supporting the bypass valve 81; and a fixing bolt 83 for fixing one side of the bypass valve 81 and the retainer 82.
A second bypass valve assembly 80 for opening and closing the second double bypass hole 33 is mounted at an upper surface of the fixed scroll 30. The second bypass valve assembly 80 is composed of: a bypass valve 81 for opening and closing the second double bypass hole 33; a retainer 82 for supporting the bypass valve 81; and a fixing bolt 83 for fixing one side of the bypass valve 81 and the retainer 82.
Valve seats 34 protruded by grooves formed as a certain shape with a certain depth are respectively formed at an upper surface of the fixed scroll 30 positioned around the discharge hole 31 and the first/second double bypass holes 33. The valve seats 34 has a constant height.
An unexplained reference numeral 35 denotes a starting bypass hole for discharging liquid refrigerant at the time of introducing liquid refrigerant, and 90 denotes a starting bypass valve assembly for opening and closing the driving bypass hole.
In the discharge valve system, in case that the scroll compressor mounted at an air conditioner, etc. is operated in a high pressure ratio, the orbiting scroll 40 performs an orbiting movement. As the orbiting scroll 40 performs an orbiting movement, a plurality of compression pockets P formed by the wrap 41 of the orbiting scroll 40 and the wrap 32 of the fixed scroll 30 move towards a center portion of the fixed scroll 30, and at the same time, volumes of the compression pockets P are gradually decreased thereby to compress gas. The compressed gas is discharged through the discharge hole 31 positioned in the middle of the fixed scroll 30 while the discharge valve 61 is opened. At this time, since the high pressure region of the hermetic container 10 maintains a high pressure state, the first and second bypass valve assemblies 80 block the first and second double bypass holes 33.
In the discharge valve system, in case that the scroll compressor mounted at an air conditioner, etc. is operated in a low pressure ratio, the orbiting scroll 40 performs an orbiting movement. As the orbiting scroll 40 performs an orbiting movement, a plurality of compression pockets P formed by the wrap 41 of the orbiting scroll 40 and the wrap 32 of the fixed scroll 30 move towards a center portion of the fixed scroll 30, and at the same time, volumes of the compression pockets P are gradually decreased thereby to compress gas. The compressed gas does not move up to the discharge hole 31 positioned in the middle of the fixed scroll 30, but is discharged through the first and second double bypass holes 33 of the fixed scroll 30 while the first and second bypass valves 80 are opened. At this time, the discharged gas has a pressure relatively lower than that of the gas discharged through the discharge hole 31. Since the high pressure region of the hermetic container 10 maintains a low pressure state, the first and second bypass valve assemblies 80 are opened.
However, in the conventional discharge valve system of a scroll compressor, the size of the first and second double bypass holes 33 can not be increased. According to this, gas compressed in a low pressure ratio can not be sufficiently discharged through the first and second bypass holes.
Also, since components constituting the discharge valve system are relatively much required, the number of assembly processes is increased. According to this, there is a difficulty in mass-producing the discharge valve system, an assembly productivity is lowered, and a fabrication cost is increased.